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Check if a row exists, otherwise insert
...erbook a flight, as it will insert a new row when there are 10 tickets max and you are booking 20.
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How to replace all occurrences of a character in string?
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std::string doesn't contain such function but you could use stand-alone replace function from algorithm header.
#include <algorithm>
#include <string>
void some_func() {
std::string s = "example string";
std::replace( s.begin(), s.end(), 'x', 'y'); // replace all 'x' t...
Windows 7 SDK installation failure
...em to be completely unable to install the Windows 7 SDK onto my machine, and the only solution I've found on the web is to make a swathe of registry changes. I've done this - still no success.
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How do I update an entity using spring-data-jpa?
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Identity of entities is defined by their primary keys. Since firstname and lastname are not parts of the primary key, you cannot tell JPA to treat Users with the same firstnames and lastnames as equal if they have different userIds.
So, if you want to update a User identified by its firstname a...
How to get the user input in Java?
...stem.in);
String s = scan.next();
int i = scan.nextInt();
BufferedReader and InputStreamReader classes
import java.io.BufferedReader;
import java.io.InputStreamReader;
//...
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String s = br.readLine();
int i = Integer.parseInt...
Getting the first character of a string with $str[0]
I want to get the first letter of a string and I've noticed that $str[0] works great. I am just not sure whether this is 'good practice', as that notation is generally used with arrays. This feature doesn't seem to be very well documented so I'm turning to you guys to tell me if it's all right –...
What's is the difference between include and extend in use case diagram?
What is the difference between include and extend in a use case diagram ?
19 Answers
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Replace all spaces in a string with '+' [duplicate]
...mal timing difference, IE has a noticeable difference. So if speed matters and you have a large set of replacements, reg exp is the way to go.
– epascarello
Sep 30 '10 at 4:27
42
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Rename specific column(s) in pandas
...' else x for x in df.columns]
Or, construct a mapping using a dictionary and perform the list-comprehension with it's get operation by setting default value as the old name:
col_dict = {'gdp': 'log(gdp)', 'cap': 'cap_mod'} ## key→old name, value→new name
df.columns = [col_dict.get(x, x) fo...
Remove stubborn underline from link
... blue underline is stubbornly persisting. I tried text-decoration: none; and text-decoration: none !important; in the CSS to remove the link underline. Neither worked.
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